Magnetic filter



C. A. MAYNARD MAGNETIC FILTER July 5, 1960 2 Sheets-Sheet 1 Filed Aug. 14, 1956 UvvJ-IU July 5, 196

Filed Aug. 14, 1956 C. A. MAYNARD MAGNETIC FILTER 2 Sheets-Sheet 2 A A III/III! II A 67/4045? /2 Mar/mp0 2,943,735 7 VMAGNETIC FILTER (Iharlesi A. Maynard; Valparaiso, 'IntL, assignor to Indiana I"- f General'Corporation' v. This inventionrelates to a magnetic filter, and more particularly to a filter or separator employing individually pre-rnagnetized balls of permanent magnet material in the fluid passage zone for separating magnetizable particles and the *like from the fluid passing therethrough.

It has heretofore been proposed, as in the Bower Patent No. 2,452,220, to provide, a magnetic separator in 'whichballs of 'a magnetizable material," su'ch as mild United States p i balls, or spheres of a high coercive force permanent magnet material are positioned in the fluid flowpassage to attract to their surfaces and retain thereon such magnetizable particles as may be contained in or carried by the fluid passing through and around a plurality of I suchballs.

"It-is a further important object of this invention to pro! vide a removable and replaceable cartridge, basket, er

the. likeof a fluid permeable, non-magnetic material containing therein a plurality .of'individually magnetized} balls of permanent magnet material for use in magnetic" filters, separators and'the like,'for'the extraction from such fluid ofmagnetiz able particles undesirably contained 7 3 therein.

It is a further important object of this invention to provide a novel, improved magnetic filter having a replaceable perforated container substantially filled with individually magnetized, permanent magnet balls.

1 Other and further objects of this invention will become apparent from the following description and appended 5 claims. a

when the p-re-ma'gnetized, permanent magnet balls re haphazardly positioned in the fluid flow passage, *as,'-for instance, in a removable perforated basket, orcartridge; of nonqnagnetic material, the balls do not. line up, as Would-be theicase in the prior arrangement with their north and south poles in contacting alignment, but be-'.

cause haphazardly arranged or oriented, they produce more effective fields of magnetic lines of flux in the spaces between the balls throughwhich the fluid must pass, thereby making possible a more efficient separation of any magnetizable particles contained in or carried by the fluid;

1 Furthermore, the permanent magnet balls employed in the separator or filter of my invention are preferably formed of permanent magnet material possessing a relatively high coercive force value, such that the balls are capable of setting up independent fields of magnet flux of relatively high density. 1

Suitable permanent magnetmaterial for 'this purpose are the polyoxides inwhi'ch ferric oxide, 'Fe o has been cornbinedin a mixed crystal with a secondary oxide such yas jbar-iu-m oxide," strontiumoxide, or lead oXide',with' Y or without small amounts ofcalcium 'oxidef" These mate 'rinsrbueagae aclasswf ferromagnetic hexagonakiron oxide" 'c'ompoii'nds, the prototype u of which is BaFe O These materials are ceramic and are commercially avail-- able uncleri: several n'a-mestincluding Indox-'-a'nd fFer roirdure,"and can be fabricated "into magnets; by' compacting ai finelyground mixture 5 of the raw." materials" followed by -sin'ter-ing; as-taught 'by Went eta1: 2,762,777;

As shown on the drawings I Figure 1 is a vertical sectional*view--of a magnetic separator involving the principles of my invention? Figure 2 is a vertical sectional view of a modified form of magnetic filter; v Figure 3 is a vertical section view of a further modification of my inventiqn; t

5 Figure 4 'is a verticalfsectional view of a still further modification of my invention; 3

' Figure 5- is a side elevational view of a removable and replaceable cartridge for use in a magnetic separator or filter. a Figure 6 is a sectional view taken substantially along the line VIVI of Figure 5. a

The'various embodiments of my invention illustrat in the drawings may be used to remove'impurities of a magnetic nature from a fluid, and more particularly from a liquid such as a lubricating oil, a hydrocarbon fuel, or the like. of my invention would be useful in filtering gasoline before its introduction into the carburetor of an engine or passage through an engine fuel injection system. 'In the handling and distribution of gasoline and other liquid fuels, there isthe possibility of the liquid taking up or acquiring magnetizable particles due to corrosion, scaling, or the like of the ferrous metal surfaces With which the liquid comes in contact. If such particles are carried with the liquid fuel into the tank of'the automotive vehicle and thence into the carburetor or injectionsystem leading into the engine, plugging of the jets and orifices of the system is likely to occur. Other applicationsof' the magnetic filter or separator will occur to thosefarniliar'with the'art, as, for'instance, for the purpose of removing magnetizable particles from lubricating oils'gin:

which such particles may be present due to wear ofmo ving-pairts'i i As illustrated inFigure 1, the reference numeral-10 indicates generallya form of magnetic filter in which a fluid passage zone provided byacasing 11 erinoh Materials fo ,this type i have extremely high coer'civ'eforcesgnbeing 'in' the ordertet1 60010 200i) oer'steds, andare e'fiiciently- :u-ised when a substantially spherical shape.: -r While other highfcoercive forcepe'rmanent magnet materials: can betused -in' my present invention, these polybxide a'r'naterials' i-have been found; to be eminently s'uitable fortliepurpose': 5i rlt" 's athefefore fan; important object of this invention to rov-ide -fa'i magnetio separaton orfilte r, for the E separation of magnetizable particles from fluids,- such 'as'liy-J drocarbon liquids and the like, in which pre-magnetized magnetic 'material having l a ilowerinlet z l z, a top," or cover13, and an upper outlet 14. The casing forming "the body portion is preferablypcylindrical forrn providedwith a flanged upper" edge lito which theftop 13 can be secured by suitable nieans"(notsliownl A. fluid such as a liquid hydrocarbon fuel, oil or the like,is

introduced through the inlet to the chamben Cv de-, fined by the-casing :lland top 13, foif ,discha rge through the'axially aligned upper discharge connectionil t,

E= In accordance with; the principlesofmypresentinven f tion, there is provided within the chamber C a perforated Patented. July 5, 1960 For instance, 'certain embodiments met r' than the outer diamet r of the'discharge conduit 1.4 and the pper Wall 18 correspondingly apertured so to. eceive the. lower end; 2!! of said conduit 14 and h s. po iti n' he basket, or ar inaxii y alignme t 7 the height of the chamber C and a coiled spring 22.is.

posit cnedfabouttheuppsr inner end 23 of the inlet. 12

with the upper end. of said spring held under compression against-the lower, imperforate wall 19 of the basket ot-urge the asket upwa dly ga ns e t p w ll 13 an holdthe's rne in p a ethereaga nst, ems-magnetize 13.8 824. of sui able permanent mag.-

netmater l; enact the same or dinerent size are positioned within the annular space S between the inner and outer perforatediwalls 17 and 16 of the basket to substantiallyfill the same. The balls 24 are only incompletely" Illustrated, and it will be understood that they would normally substantially fill the annular space S and would assume haphazard positions with respect to each; other, so far as orientation of their poles is, con

cerned, depending upon the laws of chance rather than an intentional manner of orientation. Thatis to say, north and south poles of adjacent balls might happen to line up in contact with each other but that would not be generally the, case Where the. balls are introduced into space S by random filling methods as by pouring from asou Qt: s pply o e are-magnetized balls.

The flow of fluid through the device would be that iudicatedtby the. arrows, namely into the inlet 12 for lateral and upward flow around the cylindrical apertured wall i6 through the apertures of such wall into the inteier annu ar sp cean he ce oug h P tions of the inner cylindrical wall 17 and upwardly. into the, discharge connection 14. The balls 24 would cause sufficient breaking up of the flow of the fluid through the annular spaces to bring about contact or at least close proximity between the balls and all parts of the liquid mass, thereby insuring the attraction to and the retention by the balls of any magnetizable particles contained n o ca r d; y the flu d.-

After a certain period of usage, depending upon the amount of contamination of the fluid by magnetizable particles, the basket or cartridge could be removed from the, device 10, the balls cleaned and replaced, or another fresh lotof t re-magnetized balls substituted for those previously in the basket or cartridge. In this manner, the lipid leaves the device 10 substantially free from any contaminating particles of a magnetizable character.

In the modification illustrated in Figure 2, a generally cylindrical body portion 25 preferably of non-magnetic material, is provided with a lower axially aligned inlet pipe 26 and an upper laterally extending pipe 27. The body portion 25, is of reduced diameter to provide an annular shoulder 28 for positioning thereon a perforated plate 29. The arrangement is such that the upper'end 3.0 of the-inlet pipe 216 projects into the space Slbelow the perforated plate 29, and the central portion of the plate 29- is left imperforate, as at 32, to act as a barrier A bed B isformed ofa plurality of layers of premagnetized permanent magnet. balls 24 resting upon and ex: eud u bov t e pe fora p ate 29 to ny suitable The hasket is preferably of a height less than or afile for; distributing the fluid in its upward flow on the magnetic filter bed B and the conventional filter bed 33.

In the modification illustrated in Figure 3, the device indicated by the reference numeral 35 is composed of a lower bowl-like casing 36 and an upper casing 37 and with the two casings being suitably flanged and secured together with a perforated plate 38 therebetween. An inlet pipe 39 extended downwardly through the wall of the upper casing and through an aperture 40 provided in the plate 38 for that purpose, and to the lower portion of the chamber .41 providedwy'the lower casing 36. The chamber 41 is substantially filled with individually magnetizedpermanent magnetballs 24, of varying sizes, or all of the" same size, to provide a bed or mass of such balls beneath theperforated plate 38 'through which the fluid must pass as it flows upwardly from the lower end of the inlet pipe 39. In this case, the perforated plate 38 serves merely to prevent upward displacement of the balls 24 under the action of the flow of fluid therethrough. The lower casing 36 may, of course, be readily removable for cleaning or changing the balls.

Figure 4 illustrates a gravity type of filter comprising a funnel shaped receptacle 45, preferably of non-magnetic material, having a lower axial discharge 46 and provided with a perforated plate.47 supported by the divergent wall .of theconical upper portion 48. The balls 24 are positioned above the perforated plate 47 to rest thereon and to extend thereabove to any desired height .de: pending upon the depth of the filter bed desired. Fluid is introduced above the bed through a fluid intake pipe 49 for gravity flow over and down through the bed of balls 24. 1

:Figures 5 and 6 illustrate a removable cartridge 60- of non-magnetic material. comprising a pair of spaced perdepthLf Any. conventional filter, or layer of fibrous 'rnateia uehjas thati diate a 3 m y be Positioned above the bed 13 to filter out particles not trapped by the magnetic filter bed B. In this way the filtermaterial 33 would be efiective overa lcn'ger period of time than if no magnetic bed were employed. The sp;ace'31 below the perforated plate 29 serves for a settling'out'of such particles as might tend toseparateout by gravity and thusl'essenthe load forated walls 61 and 62 and a retaining peripheral frame 63, which may suitably be rectangular in shape and provided with right angle, inturned flanges 6.4 for securernentto the. perforated plates 61 and 62. The interior of the cartridge 60 is substantially filled with balls 24 like those already described. The cartridge thus provides a replaceable unit that may be inserted in a fluid flow passage of suitable configuration to receive the cartridge and, position the same so that all of the flow of the fluid must be through the magnetic bed provided by the balls 24. This type of' filter is particularly suited for use as an air or gas. filter.

The balls 24 are preferably preformed by pressing, agglomeration or pelletizing, as previously stated, of a powdered polyoxide material, in the nature of a ferrite that is capable of acquiring and exhibiting satisfactory permanent magnet properties. Such preforming may be done in accordance with the teaching of Rodman, U.S..

Patent No. 1,239,221. The agglomerated balls are then fired and individually magnetized to provide north and south poles disposed therein and the magnetized sintered balls, are randomly filled into casings or cartridges suchv as has been described above toprovide an effective magnetic filter or separating bed. While such magnetic filters or.

separators are useful in connection with theelimination of, magnetizable particles from liquids, it will be appreciated, thatthey could bev similarly used with gaseous fluids in. which magnetizable particles might be entrained.

h While-the magnetizable-balls have been described herein as; being spherical in shape, they need not be truly spherical so long as they approximatea sphere and are capable ofassuming random positions in the filter bed or cartridge to, provide connecting interstices therebetweenfor fluid flow. Also, although different sizes of balls may be used;.,.the.,sizes will ordinarily lie between Ma and /2 inch indiameter, with about /2 inch diameter, as most satisfactory. Magnetizable. foreignparticlesin the fluid flow being filtered attach themselves to the balls and build upfiber-like agglomerations'on the surfaces of the balls that effectively extend the magnetic fields of the ballsthemselvesi A! am,

it will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

{claim as my invention:

A magnetic separator comprising a fluid passage chamber having an inlet and discharge, and a plurality of permanently magnetized balls of a ferromagnetic hexagonal iron oxide compound substantially immovably disposed with respect to each other in said chamber in the path of flow of said fluid.

2. In a magnetic filter including a container having spaced inlet and discharge passages connected thereto for fluid flow therethrough, a perforated removable cartridge within said container in the path of fluid flow between said passages, a spring spacing said cartridge from said inlet and holding the same against said discharge passage whereby fluid by-pass flow about said cartridge is precluded at all times, and a plurality of permanently magnetized balls comprising ferromagnetic hexagonal iron oxide compound contained insaid cartridge and substantially filling the same, said balls having poles randomly disposed with respect to each other.

3. In a magnetic filter having a fluid flow passage and an inlet thereinto and a discharge therefrom, a plurality of permanently magnetized spheres of a ferromagnetic hexagonal iron oxide compound in direct engagement with each other and substantially filling said passage, said spheres each having a pair of opposite magnetic poles at their peripheries, said spheres being retentively disposed with said poles arranged in a haphazard orientation with respect to the poles of the other spheres for contact with the fluid flowing therethrough.

4. A filter for filtering a fluid comprising in combination, a housing, a non-magnetic mechanical filtering medium in said housing for removing non-magnetic foreign particles from said fluid, and a plurality of permanently magnetized spheres of a ferromagnetic hexagonal iron oxide compound in direct engagement with each other and disposed in said housing in upstream flow relation to said non-magnetic filtering medium for continuously attracting and holding any magnetic impurities in said fluid, said spheres each having a pair of opposite magnetic poles at their peripheries, said spheres being retentively disposed with said poles arranged in a haphazard orientation with respect to the poles of the other spheres for contact with the fluid flowing therethrough.

References Cited in the file of this patent UNITED STATES PATENTS 1,683,780 Hulsmeyer Sept. 11, 1928 2,145,535 Vokes Jan. 31, 1939 2,436,740 Brooks Feb. 24, 1948 2,452,220 Bower Oct. 26, 1948 FOREIGN PATENTS 1,062,684 France Dec." 9, 1953 OTHER REFERENCES Nature, October 25, 1952, pgs. 707, 708, vol. 170,

No. 43.30-23F. 

